To prepare Chicken Fajitas the chicken is seared in a skillet on the stove top then transferred to the oven to finish cooking. Because of the cooking process you either need 1 oven per 2 chefs or you need to take shifts in the oven. When I cook with a group of 4 we usually prep toppings for serving as well to eliminate downtime. Decide before hand with guests who is buying the tortilla shells and optional toppings. Possible toppings include: grated cheese, salsa, guacamole, sour cream, lettuce and chopped fresh cilantro.
You can fill these as much or as little as you like depending on your family. I find 6 works well for one recipe but small kids might only eat half of one. For a dairy free version use special cheese or dice up an avocado in place of the grated cheese.